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