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