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