Upon doing a little research, I realized that this was a fairly common problem that quite a few people had run into, however, my solution was not the same as all the solutions that I found. One solution that I found online was to not use the minified version of s3slider. The minified version of s3slider apparently contains some errors, so using the default version will oftentimes solve whatever error you’re receiving. If this solution doesn’t work for you, you may have the same problem I was having. My problem stemmed from where s3slider was being loaded on the page. It was being loaded before the jQuery library was being loaded. By updating my HTML to load jQuery first, I was able to resolve the issue.
s3slider is not a function in my case was the error being caused by the jQuery library not being initialized first. Easy fix, by just moving the s3slider.js file above the jquery declaration.