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