Recently I created a small example of a GraphQL server (built with http://sangria-graphql.org) which is based on event-sourcing and CQRS:

https://github.com/OlegIlyenko/sangria-subscriptions-example

It does not use any event-sourcing library or anything like this, so it may be more approachable for people who are learning even-sourcing and GraphQL.

Interesting aspect of this project is that it uses GraphQL subscriptions to expose and stream the events (with Server-sent Events).