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