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