Can a person paying tax under composition levy, withdraw voluntarily from the scheme? If so, how?

Yes. The registered person who intends to withdraw from the composition scheme can file a duly signed or verified application in FORM GST CMP-04.
Every person who has filed an application for withdrawal from the composition scheme, may electronically furnish, a statement in FORM GST ITC-01 containing details of the stock of inputs and inputs contained in semi-finished or finished goods held in stock by him on the date of withdrawal, within a period of thirty days of withdrawal.