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