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