Junos doesn't use XSLT to convert the XML configuration into the text configuration, and the processing that it does use (which I believe is proprietary) is not exposed outside of the source code.
You can craft a template that makes a best effort conversion like you showed in your post, or you can load it into a Junos box and pull out the text configuration. I'm not aware of any other alternative. I guess there are the config schemas as well, but I don't think that will give you what you're looking for.