In order to visualize site map as a flowchart, you can use Site Visualizer software.
It has 30-days full-featured trial period, so you can create visual map of any existing website absolutely for free.
After installation, create new project, type website URL you need to crawl, then lick Start tool button. After the crawling will be done, click Draw button on the Visual Sitemap tab. When the visualization will be drawn, you can highlight links of any page by clicking on its rectangle. Outboind links with rel="nofollow" attribute draws with dotted line:
Click on Save button in order to save the visual sitemap to an image file: PNG, JPG, BMP, etc. More info you can find at the Quick Start Guide.