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