Oh biting is horrid isn't it? so nearly always it is about communication....he will be trying to tell you something, you just need to work out what it is. But for the next couple of weeks i would suggest a member of staff shadows him constantly.(difficult but necessary of you don't want complaints!)
Teach him how to play/use good eye contact/praise when he's done something right/try to ignore bad behaviour. don't react too much if he bites...sort out the bitten child first be very clear with good facial expressions how you are feeling. Teach the other children to say no or stop if needed loudly (and practice!) this will give the staff a headsup! and give them a way to play without fear. Try to avoid the timid ones playing with him until this is settled. Don't use sentences like hands are for playing not for biting ..he won't understand it!!!!
If he has had any mouth issues/trauma there may be a deeper problem...he may need feedback stimulus from the biting and so may need a chew toy. Speak to your Ed Psychologist for more info.
Please try to avoid staff being negative with him...he needs positive affirmations and these need to be done in front of the other children so that they understand he can be well behaved and play well, otherwise they will start to avoid him...which will cause hurt and frustration and potentially more biting to get them to react to him.
Try doing an ABC chart to work out if there are any triggers.
Keep him occupied with LOTS of open ended sensory activities.