1) Log File :Follow these steps to download logs,
1. Go to System-> Log Settings.
2. Enter com.miniorange.oauth in class path field and select Debug in type.Click on add.
After these steps, perform single sign-on again to record logs. Then download support zip using these steps,
1. Go to System -> Troubleshooting and support tools.
2. Proceed to create support zip.
3. Keep only Logs files option selected.
4. Click on Create zip and then Download zip.
2) SAML Tracer Log File : Click HERE to get steps to capture Tracer logs.