By default whenever you like something on your page, you will be liking it as your page. If you want to like posts on your page as yourself, you are going to have to flip a switch. This setting has moved around a few times over the years. As of today, this is where you can find it.
- Login to Facebook
- Navigate to the page you are an Admin of
- Click on Settings in the top right corner
- Click on the Post Attribution category
- Change the setting from your page to you