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)(11,15)(12,16)(13,14)(17,18)(19,28)(20,25)(21,35)(22,27)(23,26)(24,31)(29,45)(30,39)(32,48)(33,44)(34,43)(36,40)(37,42)(38,47)(41,46)(1,3,4,8)(2,5,6,7)(17,19,22,31)(18,24,27,28)(20,32,34,46)(21,30,23,36)(25,41,43,48)(26,39,35,40)(29,37,47,33)(38,42,45,44)(10,14)(15,16)(17,20,22,34)(18,25,27,43)(19,29,31,47)(21,33,23,37)(24,38,28,45)(26,42,35,44)(30,46,36,32)(39,41,40,48)(2,6)(5,7)(9,11,13,12)(10,15,14,16)(17,21,22,23)(18,26,27,35)(19,30,31,36)(20,33,34,37)(24,39,28,40)(25,42,43,44)(29,46,47,32)(38,41,45,48)(3,8)(5,7)(9,12,13,11)(10,16,14,15)(19,30)(21,23)(24,40)(26,35)(28,39)(29,46)(31,36)(32,47)(33,37)(38,48)(41,45)(42,44)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.