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