Due to him being the narrator we don't know what he looks like. Though I imagine him as tall with dark hair and eyes. He manages to have positive relationships with most characters and hides it from the ones he doesn't.
Gatsby is a taller man with a dark brown hair and is mysterious to the narrator though is known by other characters due to the parties he throws. Lives at west egg.
Daisy has blonde hair and is seen as joyful and flirtatious. She has a relationship which is seen as abusive with her husband tom but doesn't show it.She had a child and used to live in Chicago.
Tom Buchanan is a tall stronger man who has a good relationship with many people though cheats on his wife and possibly even abuses her.
Jordan Baker is a well known character by both of the Buchanan's and is very well known for being a athletic golfer.
Myrtle has a very strong relationship with Tom Buchanan and may possibly be using him for his money. She seems friendly to new people as shown with Nick.