Salesforce Sites guest users can access their saved submissions without the need for specific sharing rules on the "Submission Draft" object. It's recommended to remove the sharing rules from your Salesforce organization. Here's how!
Step 1: To configure Sharing Rules, navigate to Setup > Security Controls > Sharing Settings.
Step 2: Locate the Submission Draft object.

Step 3: Remove the Site Guest User role. The exact name will change according to the sites configured in your organization.
Step 4: Click the Recalculate button to force a reevaluation of the sharing rules in your organization.
Step 1: To configure Sharing Rules, navigate to Setup > Security Controls > Sharing Settings.
Step 2: Locate the Submission Draft object.
Step 3: Remove the Site Guest User role. The exact name will change according to the sites configured in your organization.
Step 4: Click the Recalculate button to force a reevaluation of the sharing rules in your organization.