There is a CSS property to apply a wrapping behavior for long name labels. You can see it here .
Here is the content of a small CSS that you can easily apply on your model for a quick try : create a new file 'demo.css' in your project, fill it with following content and drop it onto the diagram you want to customize.
isNameWrap : true
I let you read all the documentation on wiki to get the full support for CSS.