Exiting/Starting the Terminal (El Capitan)
When the Shell exits, it means that you are done. So one option is to close the window and manually start another one (or you can simply press cmd+N to automatically open another shell).

Another option that can save you some time is to make Terminal automatically close the tab after the exit process has been performed properly.
Open Terminal Preferences > Profiles > Select your profile > Shell tab > When the shell exits --> Close the window. In such a way, if you want to start again your shell (after having exit) you should just open another one.