One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,8)(3,6,4,7)(9,10,13,16)(11,14,18,22)(12,15,20,24)(17,21,19,23)(25,26,31,32,30,36,29,35)(27,33,39,46,37,50,40,48)(28,41,44,52,45,34,42,47)(38,51,53,56,43,49,54,55)(1,3,5,4)(2,6,8,7)(9,11)(10,14)(12,19)(13,18)(15,23)(16,22)(17,20)(21,24)(26,32)(27,37)(28,42)(29,31)(33,48)(35,36)(38,53)(43,54)(44,45)(46,50)(47,52)(49,51)(1,3,5,4)(2,7,8,6)(9,12,13,20)(10,15,16,24)(11,17,18,19)(14,21,22,23)(25,27)(26,33)(28,43)(29,40)(30,37)(31,39)(32,46)(34,51)(35,48)(36,50)(38,45)(41,49)(42,53)(44,54)(47,56)(52,55)(1,3,5,4)(2,6,8,7)(12,20)(15,24)(17,19)(21,23)(25,28,29,42,30,45,31,44)(26,34,35,52,36,41,32,47)(27,38,40,54,37,43,39,53)(33,49,48,56,50,51,46,55)(1,4,5,3)(2,7,8,6)(10,16)(11,18)(15,24)(17,19)(25,29,30,31)(26,35,36,32)(27,39,37,40)(28,44,45,42)(33,46,50,48)(34,47,41,52)(38,54,43,53)(49,56,51,55)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.