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