Graph explorer: 

https://developer.microsoft.com/en-us/graph/graph-explorer

https://graphexplorer.azurewebsites.net/

News from ignite 2019:

https://developer.microsoft.com/en-us/office/blogs/ignite-2019-microsoft-graph-news/

 

Resources for MS graph API:

https://docs.microsoft.com/en-us/graph/security-concept-overview

https://github.com/microsoftgraph/security-api-solutions/tree/master/Samples/PowerShell

https://www.petri.com/exploring-office-365-graph-explorer

 

How to access Azure AD using Microsoft GRAPH:

https://www.bing.com/videos/search?q=how+to+access+azure+AD+using+microsoft+graph&qpvt=how+to+access+azure+AD+using+microsoft+graph&FORM=VDRE

Previous:

https://docs.microsoft.com/en-us/azure/active-directory/develop/active-directory-graph-api-quickstart

 

New MS graph API add-on for splunk:

https://techcommunity.microsoft.com/t5/Security-Privacy-and-Compliance/Introducing-the-new-Microsoft-Graph-Security-API-add-on-for/ba-p/815972