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