Ethics behind communicating research after end of project and unemployment
If your degree is not finished and your advisor feels you should comply with the request to give a presentation, you may not have a strong voice in the matter. 

To put it bluntly, college professors are used to getting work from students for bargain prices. And, because they control the gateway to a degree, they usually get what they want. That is a sad reality of academia. Not all professors are like this. But some indeed are. This is why academia.SE is full of questions to the tune of "My advisor/professor took advantage of my labor. What should I do?"

I would consider two points here:


If you have a good relationship with your advisor, address these concerns to him/her. In writing (email) is even better than verbally perhaps. Mention that you cannot do extensive work for free. Express your opinion professionally. You do have a voice here (albeit one that might be ignored). 
Be willing to compromise. If your professor still asks you to comply, outline some parameters you would like to have in place. (Two examples below). 


I would be willing to work 10 hours a week on this presentation, but I do not feel that I can devote more time to the project and still complete my degree in a timely fashion.
I want to partition some of my time towards seeking full time employment for after graduation. Is their an avenue for me to do such?



In short, you have a voice in this matter, but your professor might disregard your opinion so as to retain an industry connection. This is part of the politics of academia as a student.