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