One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,6)(4,5)(7,8)(9,10,16,20)(11,15,19,14)(12,17,26,33)(13,18,28,35)(21,25,32,24)(22,30,36,29)(23,31,27,34)(37,40,38,39)(9,11,14,10,16,19,15,20)(12,17,24,32,26,33,25,21)(13,18,29,36,28,35,30,22)(23,38,39,34,27,37,40,31)(2,5)(6,8)(9,12,14,24,16,26,15,25)(10,17,11,21,20,33,19,32)(13,27,29,40,28,23,30,39)(18,34,22,38,35,31,36,37)(9,13,14,29,16,28,15,30)(10,18,11,22,20,35,19,36)(12,23,24,39,26,27,25,40)(17,31,21,37,33,34,32,38)(1,3,4,7)(2,6,5,8)(13,28)(18,35)(22,36)(23,27)(29,30)(31,34)(37,38)(39,40)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.