There is no signature on an e-filed tax return. You didn't sign it when you filed it. If someone is asking you for a signed copy, apparently they never heard of electronic filing.
The "electronic signature" was the prior-year AGI that you entered when you e-filed, but that does not appear anywhere on the forms. The Electronic Postmark page in the PDF of your tax return shows that it was filed.
You can print your tax return from the PDF, sign it at the bottom of page 2 of the Form 1040, and give the signed copy to whoever is asking for a signed copy.
