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