Users can preselect an authorization set (1). And, later on, modify the set. As a user, I want to see how the original authorization set differs from the one I changed. So I can see which permissions are disabled/enabled in permission. The totality of rules is around 90.
With so many rules there can be a very high density of information with potentially a lot or very little change. However, since the focus is on the delta (i.e. difference rather than actual details) between the previous and current rule set, the visual design is on how to highlight the disabled/enabled permission differences.
The easiest approach is to compare the two sets of configurations side-by-side and highlight those rows that are different. You can simplify this so that either the previous or current configurations are shown as well.
Alternatively you can try to divide the entire set into smaller sections or chunks, which means you can provide a more concise summary without losing too much details (e.g. if you just summarized the number of changes it might not be meaningful enough). You'll also have to indicate what the change in the permission is (i.e. whether they have been enabled or disabled).
As you can see, there are a number of potential design strategies and solutions that can meet the brief requirements that you have outlined, but to come up with a more specific solution requires a better understanding of the use case and constraints.