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