One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(9,10,14,20,12,28,30,31,16,21,13,19,15,18,29,32)(11,17,25,36,23,39,33,38,27,37,24,35,26,34,40,22)(2,4)(5,6)(7,8)(9,11,13,24,12,23,29,40,16,27,14,25,15,26,30,33)(10,17,19,35,28,39,32,22,21,37,20,36,18,34,31,38)(6,8)(9,10,16,21)(11,22,27,38)(12,18,15,28)(13,31,14,32)(17,33,37,40)(19,29,20,30)(23,35,26,36)(24,39,25,34)(2,4)(9,12,16,15)(10,18,21,28)(11,23,27,26)(13,29,14,30)(17,34,37,39)(19,31,20,32)(22,35,38,36)(24,40,25,33)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.