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