From a deacon reader:
I assume a permanent deacon’s choir dress would be cassock and
surplice, just like a priest. But if he were to receive communion,
would he bring a diaconal stole and put it on at the appropriate time?
A deacon is a deacon is a deacon. He therefore uses proper clerical dress when in choir.
He wears the cassock, with the Roman/military collar, surplice and biretta.
To receive Holy Communion, put on the stole in the manner of a deacon just before you receive and take it off after you have received. Don’t wear it in the entrance procession or recessional or during the whole Mass. Bring the stole in draped over your left arm, or put it in place at your kneeler before Mass begins.