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