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