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