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