Unfortunately, the code size you're looking at is Facebook's Javascript APIs. Those are not files we've created, or are able to modify in any way.
Though we do agree that smaller is always better for a web page, 60KB is generally not a huge amount for a site, anymore. Additionally, any modern browser will cache the javascript file and test to see if it needs to be updated/downloaded on subsequent page loads. Therefore, the download of the file should be relatively rare (every day, maybe) not every pageload. The speed of that code executing will remain constant though, and in this area Facebook's Javascript API isn't always the fastest.
Hope this information helps!