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