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