If snapshot was created recently, then you can navigate to Tasks&Events tab in Monitor Client for the VM with snapshot and search for the snapshot creation task initiator. For historical data reporting, you can use this predefined report template > Infrastructure Changes Audit
Kevin, if you want to track the creator of a really old snapshots which was created months ago, then it might not be possible to do with Veeam ONE, however all recent snapshots should be properly recorded by Veeam ONE, so either Tasks & Events tab or infrastructure changes report should help!
BTW, is VM snapshot usually created by someone else rather than a VM owner?