Toggle Event Delegation
The code looks pretty good. There are only a few suggestions I have about it.

While it doesn't depend on Babeljs, it appears that Array.from() is part of the Ecmascript 2015 (6th edition) Standard1. So if you really wanted to make this code ES-5 compliant, you would need to remove that. For example, this example suggests using .slice.call:

So instead of 


Array.from(selectorList)
  .forEach(function (selector) {



You would need to do something like 

[].slice.call(selectorList)
    .forEach(function (selector) {




The naming of selectorList is a little misleading, since querySelectorAll returns a NodeList. A more appropriate name would be selectedNodes or something similar. Similarly, selector is misleading, since it is typically passed a DOMNode object.

1https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/from#Specifications