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