Sign onto the TurboTax website with the User ID you used to create the account - https://myturbotax.intuit.com/
The Form 4868 will be available to view or print when you use Print Center.
Click on Tax Tools on the left side of the online program screen. Then click on Print Center. Then click on Print, save or preview this year's return. Choose the option Include government and TurboTax worksheets