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