Generating a UML sequence diagram

You can export the contents of the Call Graph panel as a picture to get the structure of the calls for the given profiling run. Been exported as an UML this will present only a part of all possible calls and another profiling run may well end with a different diagram.

Any good reason for the functionality you are asking for? (I am wondering, because SmartBear's Support may ask you the same question in order to have a valid user story that can be used as a reason for registering a new feature request in their database.)