Yes, you are welcome to use the figure in any means you want, provided that you keep the watermark. This is summarized in the Creative Commons attribution share-alike license.
If you prefer to use watermark-free images, you can subscribe to Mind the Graph for only 5 USD/month and have access to full library of images and create unlimited figures.
The content stored in and created with MindtheGraph.com are available under a free culture Creative Commons license. This means that we allow you to publicly present the infographics created with the MindtheGraph editor and use the bitmaps available in the website, provided that MindtheGraph is cited in text and it's logo image. Modifications on prior work may also be performed, if you agree to also share the modified work. By using the website, you also allow other MindtheGraph users to use your images and create upon them, under the same terms. This is known in the CC community as "attribution share-alike 4.0 licensing". More details about this license can be found here: http://creativecommons.org/licenses/by-sa/4.0/