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