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