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