See Snapshots on the Edge SWG (ProxySG) & ASG appliances.
The following is the Advanced URL that will display Snapshots:
https://ProxyIP:8082/Diagnostics/Snapshot
This will give a list of:
1. 100 latest Snapshot sysinfo created everyday
2. 100 latest Snapshot sysinfo_stats created every hour
3. Any custom Snapshots created as per defined settings
These can be downloaded individually or downloaded altogether as needed.