I would be very careful about this. Pus is a sign of infection and yellowish clear fluid is what pus looks like. People with diabetes are prone to getting bacterial infections in their feet which heal slowly and foot ulcers are one of the major complications of the disorder. One problem in diabetes is that circulation to the feet is impaired which makes healing more difficult and amputations can occur if the feet are not taken care of properly. I would get this checked out.
I'd like to suggest that you ask your question on our diabetes site. I know foot injuries are more complicated for diabetics and since I'm not an expert on diabetes, I'd be hesitant to advise you. Someone there should be able to help you.