Finaly managed to Make SEM Shows Nodes Names Instead of IP address doing the following
1- Create a reverse DNS Zone for every network (Subnet) in your environments
.2-Create A host (A) DNS record for every device which you want to add to SEM. make sure to enable the option of Create associated pointer (PTR) record ,when creating the Hosts Records
3-configre DNS on your SEM Appliance
4-Add your nodes to SEM ,if the nodes already added to SEM and shown with IP address ,remove the node and re-add it after you follow the previous steps.