You cannot. Unless you signed up for a service that will track the phone, or had an app(s) installed on it to track it, it is gone.
You can try contacting your carrier/service provider and get them to see if they can pin down a general location for you, but that is up to them. You should really get them to also turn off the service so you don't get a huge bill.
OH and change all your passwords for any service/account you used on that phone.