My the has as CSS override option in the the options, as many themes do. I basically changed the styling of some elements there, so it would override this plugin's default styling. A separate .css for plugins would be a fine place too, as long as it will be loaded after the styling of this plugin or it would be much harder to override the styling (using '!important' is bad practice).
I also used the different shortcodes documented under the [help] page of this plugin to separate some of the elements. My theme uses VisualComposer so I was able to easily fill a page with multiple columns of info (without the hassle and limitations of widgets and sidebars), like these three columns for one page; rankings || upcoming matches || text content (basically Call to Action buttons to register/login).
On another page two columns; predictions table || bonus questions.
Basically by moving things around and overriding some CSS I got it neatly integrated into my theme/site.