Hi there - I'm a new user and was having a similar issue. The web version of xfinity home didn't have the toggle buttons initially. So, I was able to get around this by:
1. Going to the mobile home app
2. Going to automation
3. Clicking on the rule I wanted to turn off
4. Ignoring the message that said "This rule was created in an older version and can only be edited on the web"
5. Toggling it off, until it turned light gray in the app.
6. When I refreshed the desktop version, the toggle button appeared, along with days of the week, the ability to edit and to delete the rule entirely.