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