There is no actual signature. When you efiled you signed by entering the prior year AGI to verify.
If you need to give someone a signed copy you print it out and sign it in ink yourself.
The only thing in your return is in the PDF of your TurboTax return, the last page of the federal return should be an "electronic postmark" that shows your name, Social Security number, the date and time that you e-filed the return, and the date that the IRS accepted it.
