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)(11,20,24,16)(12,25,29,40)(13,18)(14,30)(15,19)(17,27,34,28)(21,37)(22,35,23,32)(26,36)(31,38)(33,39)(1,3,5,2)(4,7,8,6)(9,11)(10,16)(12,26)(13,23)(14,22)(15,24)(17,33)(18,35)(19,20)(21,28)(25,31)(27,39)(29,38)(30,32)(34,37)(36,40)(1,4,5,8)(2,6,3,7)(9,12,14,28,15,29,13,27)(10,17,18,25,19,34,30,40)(11,21,23,26,24,39,22,38)(16,31,32,33,20,36,35,37)(2,3)(6,7)(10,18,19,30)(16,32,20,35)(17,25,34,40)(31,33,36,37)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.