@PoPSiCLe Thank you for replying, i already have the page (http://www.jeux4u.com/sitemap.xml) But i want to make it organised and more beautiful like this one: (www.apple.com/sitemap/)
They're not really the same thing. The Apple-one is a "sitemap", by all means, but for all intents and purposes, it's a directory for the site (categories, subcategories, and links to all important bits). The sitemap you link to on your own site, is, as the information box on top says, for bots and spiders to get a simple, easy overview of the content on your site. It's not really supposed to be read by humans at all. If you want something akin to the Apple one, you'll have to either look for directory-plugins for WP, or code it yourself. You can of course base it on the XML-file, and even interprete it and pull the data from it, but most likely you'll want to create the layout yourself, and use either database-entries, or arrays to populate the different sub-categories.
If you are using wordpress then you can use the 'google xml sitemap' plugin to generate an xml sitemap; if you run linux, then I have a little script that I made available that you can turn your xml sitemap into a list of html links to put in a wordpress page: http://jonathansblog.co.uk/xml-sitemap-html-simple-bash-script