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