IPA: /ɡrəˈfɪtɪst/
KK: /græˈfɪtɪst/
A person who creates graffiti, often by painting or drawing on walls or other surfaces in public places.
The graffitist left a colorful mural on the side of the building.
Graffitist is formed from "graffiti" (from Italian *graffito*, meaning a scratch or scribble) and the suffix "-ist" (meaning a person who practices or is concerned with something). A graffitist is a person who creates graffiti, often as a form of artistic expression.
Think of someone who creates 'scratches' or 'scribbles' ('graffiti') and is an 'artist' ('-ist') — that's what a graffitist does.
No commonly confused words.