Go in for what may be graphic language (5)
I believe the answer is:
argot
'graphic language' is the definition.
'argot' can be an answer for 'language' (argot is a kind of language). I am not certain of the 'graphic' bit.
'go in for what' is the wordplay.
'in for' is an insertion indicator.
'what' becomes 'art' (I can't justify this - if you can you should give a lot more credence to this answer).
'go' placed inside 'art' is 'ARGOT'.
'may be' is the link.
Can you help me to learn more?
(Other definitions for argot that I've seen before include "Language of a particular group" , "Specialised language" , "Groat (anag)" , "Special jargon of a group" , "Patois, vernacular" .)