This is a somewhat confusing thing to achieve, highlighting liquid templating code in a code block, and made even more confusing by the title. Take this example from this article about I wrote about mephisto:
To actually display the liquid template code you have to get crazy with the curly brackets; the code in the markdown (in my case) file actually looks like:
Typing that above leads to a sweet infinity effect, but do yourself a favor and don't copy/paste that, just take it from this post on github, because to actually type that I had to use
“. Of course a proper way to do would be to extend markdown/textile in pygments to support the liquid templating language, but that's for another day.