Hi,
You need to remove the access of Page 16 Chart of Accounts from the Permission set that this user group is using.
If the permission set that this user group have assigned is also assigned to other users/user groups then changing it will affect others also. In that case create copy of this Permission set, modify the copied i.e. removing page 16 permissions and then assign it to this user group.
Just adding another thing that there is chart of accounts report as well. May be you should restrict its access as well.
