There is not an easy way to do this.  Salesforce has lots of functions in the tasks and events arena that cannot be very well reproduced in Skuid.  The send notification field that can be exposed in Skuid only works on initial event creation.  On update the notification doesn’t fire. 

I think you’d have to create some custom process (workflow,  flow, apex?) that fires the email to all participants in the event.  Then build a button in Skuid that triggers this custom process.  Its pretty ugly,  but its what it is… 

Thanks for the reply Rob. haven’t start working on this requirement, ill update the post once done.