No matter how quickly you clean up liquid, it will get into parts you didn't think it could. Also, you should always let a laptop or other device have time to dry out while not on.
Leaving it on could have caused more damage, and if any of the liquid gets to the battery, that can be even more of a problem.
You should check inside (both in the laptop and in the keyboard area) to make sure there is nothing at all inside. If you find anything at all, carefully clean it and leave it open to dry for a day or two. Also, be sure it is turned off when you are cleaning it out.