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