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