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)(11,18)(12,16)(13,22)(14,17)(15,20)(19,24)(21,23)(25,26,30,34,29,33,41,47)(27,31,37,44,36,43,51,55)(28,38,40,52,39,32,45,46)(35,48,50,56,49,42,53,54)(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)(26,31)(28,35)(29,36)(30,37)(32,42)(33,43)(34,44)(38,48)(39,49)(40,50)(41,51)(45,53)(46,54)(47,55)(52,56) involution — undirected(2,6)(3,7)(9,12,14,13)(10,16,17,22)(11,19,20,21)(15,23,18,24)(25,28)(26,32)(27,35)(29,39)(30,40)(31,42)(33,38)(34,46)(36,49)(37,50)(41,45)(43,48)(44,54)(47,52)(51,53)(55,56)(2,6)(5,8)(11,20)(15,18)(19,21)(23,24)(26,33)(28,39)(31,43)(34,47)(35,49)(40,45)(44,55)(50,53) involution — undirected(9,13,14,12)(10,16,17,22)(11,21,20,19)(15,23,18,24)(27,36)(31,43)(35,49)(37,51)(42,48)(44,55)(50,53)(54,56)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.