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