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