This dex.js visual is based upon the clustered force layout which uses two custom forces 'cluster' and 'collide'.
Here is the example on which the base visualization is based.
https://cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js
https://cdnjs.cloudflare.com/ajax/libs/jqueryui/1.12.1/jquery-ui.min.js
https://dexjs.net/js/dex-jquery.js
https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/js/bootstrap.min.js
https://dexjs.net/js/dex-bootstrap.js
https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js
https://dexjs.net/js/dex-libs.js
https://dexjs.net/js/dex.js