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