One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,6)(3,7,8,5)(9,10)(11,14)(12,13)(15,16)(17,18)(19,24)(20,25)(21,35)(22,28)(23,27)(26,33)(29,39)(30,43)(31,42)(32,41)(34,44)(36,48)(37,45)(38,46)(40,47)(1,3,4,8)(2,5,6,7)(17,19)(18,24)(20,30)(21,36)(22,38)(23,32)(25,43)(26,39)(27,41)(28,46)(29,33)(31,37)(34,47)(35,48)(40,44)(42,45)(10,13)(14,16)(17,20,22,33,23,34,37,21)(18,25,28,26,27,44,45,35)(19,29,31,30,32,36,38,47)(24,39,42,43,41,48,46,40)(17,21,37,34,23,33,22,20)(18,26,45,25,27,35,28,44)(19,30,38,29,32,47,31,36)(24,40,46,48,41,43,42,39)(9,11,12,15)(10,14,13,16)(18,27)(24,41)(25,44)(26,35)(28,45)(39,48)(40,43)(42,46)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.