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