Are TI graphing calculators permitted on the FAA knowledge exams?
The document you cite actually goes on to explain what the procedure is for calculators, and when testing centers can prevent you from using your own (you'll be provided a loaner):


  
  Testing centers may provide a calculator to you and/or deny use of your personal calculator based on the following limitations:
  
  
  
    a. Prior to, and upon completion of the test, while in the presence of the Unit Member (formerly referred to as proctor), you must actuate the ON/OFF switch and perform any other function that ensures erasure of any data stored in memory circuits.
    
    b. The use of electronic calculators incorporating permanent or continuous type memory circuits without erasure capability is prohibited. The Unit Member may refuse the use of your calculator when unable to determine the calculator’s erasure capability.
    
    [...]
  


Basically, you can bring a graphing calculator and wipe it, but unless the center is able to confirm that you've removed all stored memory, they're probably just gonna say "nah" and hand you a basic calculator. There's a pretty good chance that your graphing calculator falls under the "permanent or continuous type memory circuits" category anyway.