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