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