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