Unlike the other browsers, for Safari we do not have any executable. Rather, enable the automation control on Safari. For enabling, follow the steps below:

For High Sierra and later

Run safaridriver --enable once.

Sierra and earlier

If not done already, make the Develop menu available.

Open Safari Browser ➙ Preferences, and on the Advanced tab, select "Show Develop menu in menu bar".

Navigate to Develop ➙ Allow Remote Automation.

Authorize SafariDriver to launch the XPC service that hosts the local webserver. To permit this, manually run /usr/bin/safaridriver once and follow the authentication prompt.