I am a salary base 40 hour per week employee. I am responsible to be on call from the time I leave a t 5 pm, and on call all weekend long. Should I be getting payed for the hours worked over 40

That depends on what you mean by salaried. Many people mistakenly use salaried and exempt as being interchangeable, but they are not.

If you are salaried exempt, there are no circumstances whatsoever in which you are entitled to be paid anything more than your regular salary, no matter how many hours you work or are on call.

If you are salaried non-exempt, then you have to be paid for any overtime that you work and, depending on circumstances, possibly for some or all of the on-call time.