How to select an existing preset for a new site?

I add a new site and wants to use an existing transfer preset. I choose the preset under the transfer setting but how do I save it for the site so I don't have to select it again every time?

Do it the other way around: Select your preset in Preferences, click Duplicate and change Hostname mask and Username mask as needed for the new site.
https://winscp.net/eng/docs/ui_pref_transfer