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