Although I haven't seen anybody doing that. but I must first ask: what's the harm in doing it? A good presentation is all about making a commoner understand your work, experts would definitely understand the terms and literature. but a good presentation is always understood by the common people who will be present to attend the defense session. I had used some diagrams in my master's presentation. but I guess the best person who you should ask is your supervisor. And all the best for your defense.

Is it possible to use Hand-drawing to generate diagrams and put them in the thesis defense presentation?

See no reason why you can't - but some points you might want to consider include:

To my mind, it is quite possible.

Thank you all for your inputs. Dear Han, really significant points to consider thank you.

Is it possible to use Hand-drawing to generate diagrams and put them in the thesis defense presentation?

Yes i think its possible and permissible 

Its possible, if its your pure idea, then it ll be perfectly alright. in other case, you have to cite reference as well

It would depend on the purpose, if you are showing your process - such as mind mapping - you likely should include it.  If it is something that would better fit a table, chart or diagram then likely that would be the way to move forward.  

Thanks all for your answers