I am not familiar with the code for that particular applet- it's embedded and saved in the applet archive as a .jar, which is essentially just an executable file. I don't think that the applets are open source. However, you could also just link to the applet.
Alternatively, if you are familiar with html and can work with it on your site, the applet itself should be [[here]]
. Though my Java is currently a little buggy, so I'm not sure if the .jar will work if downloaded in that way, it may be worth a try. Once you have the .jar, you should be able to embed the applet. If you're unfamiliar with html, you could try searching things like "html embedding a java applet".
I'm a little rusty on html and source code, though, so if this doesn't work, be sure to ask!
Good luck, and hope this helped!