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