Looking for some bare bones ERD insight

Currently working on a project for a database class and would like some input on setting up the ERD. I really want to get this right so I can get a good base for the project. It is for an insurance company. Here are some of the details:

-Any policy holder can have more than one policy
-Each policy is served by one sales rep
-A rep may serve many policies, however, since the company has different organizations for Farm and Auto insurance a policy holder may some times be served by more than one rep

Initially I had it set up like this(Parenthesis for relationships):
CUSTOMER(Supplies)POLICY(SERVES)AGENT

But now I think it may look better like this
AGENT(Supplies)CUSTOMER(Buys)POLICY

Any help or input is greatly appreciated