Your question is somewhat difficult because it is very specific. I was looking for in the dictionary and I wonder if it could be something like "modeller", maybe. or "modellor". I am inventing. "Maquetteur", maybe. I have seen that where there is no other expression in english to express an idea, you borrow it from a foreign language.
I suspect Mora is right, except that it should be in plural "Graphics Artist" or "Graphics Designer." Violence on TV can be graphic. Someone who lays out magazine covers on a computer is working with graphics.
Layout artists (son diseñadores graficos claro, que maquetan)
A layout artist deals with the structure and layout out of images and text in a pleasing format for printed media. This can include magazine work, brochures, flyers, books, CD booklets, posters, and similar formats. For magazines and similar productions, color, typeface, text formatting, graphic layout and more must be considered. Is the chosen typeface good for long term reading, or will the eyes get tired? Does that title typeface fit the feel of the rest of the article? Are the photos arranged in such a way that is pleasing to the eye, and directs the reader in the right flow or direction? These are just some of the questions a layout artist must ask themselves. Page layouts are usually done by art directors, graphic designers, production artists or a combination of those positions. Entry level layout work is often known as paste up art. Entry level layout graphic designers are often known as production artists.
I believe that 'graphic artist' (or designer) is the correct term, and that 'graphics artist' is not correct. I invite you to google the terms to confirm. 'Layout artist' is fast becoming an obsolete term, as 'paste-up artist' already is. Layout work and past-up work no longer require a different person than the graphic artist, ever since the conversion to computers.
'Graphic' comes from the Classical Greek 'to write', it refers to all the arts that include any form of 2 dimensional visual representation. 'Graphic arts' is sometimes shortened to 'graphics', and sometimes graphic representations such as drawings or posters are also called 'graphics'. Graphic also means 'described in realistic detail, vivid' , but that is another context.
2. "Graphic" Artist and "Graphics" Artist both bring up lots of articles in Google, and the use of "graphic" is becoming more and more common, because Americans are too lazy to pronounce the final "s". I am just a purist fighting a losing cause. 10-20 years ago, to my recollection, (and when PC's were fairly new to the profession, everyone said "graphics." Part of the problem, I believe, is TV commercials for schools advertising training. If you omit the "s" you save 0.1 seconds.
I suspect this is the same phenomenon that turned "transducir" to "trasducir" to "traducir," which is now standard. If enough people say it, some day "maomeno" will be in the dictionary, and people will have to go to an etymological dictionary to discover that it used to be "más o menos" back in the first part of the 21st Century.