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