Some theory behind the scene is described in this article.

If you have user permissions in AD, you can map GUIDs to GPO names. Here is the procedure:

1. Export your GPOs to CSV (Get-GPO -all | Export-Csv -Path gpos.csv)
2. Open the csv file exported by the Parse-GPO.ps1 script in Excel
3. Insert gpos.csv to a new sheet (Sheet1)
4. Insert a column B in the result of the script
5. Fill up cells of your B column with =VLOOKUP(MID(A3,FIND("{",A3)+1,36),Sheet1!$A:$B,2,FALSE)

Of course you can do the same in PowerShell if you prefer. Up to you :)

GPOPermissionsCollector.ps1 - collects permissions for GPOs and allows you to find anomalies. Requires domain access.