1. Open your DocuSign account on a separate tab/window, and Click on the ‘Admin’ Tab.
Make sure you are logged in the right DocuSign account ;).

2. Once in the Admin Menu, look for the ‘Connect’ item on the menu [yes, the one to the left] and click on it.

3. Finally, in the ‘Connect’ Section, you should already see the ‘DocuSign App Launcher‘ Item added (which should be active).

Some Documentation References:
DocuSign eSignature on Salesforce
Getting Started With DocuSign eSignature for Salesforce