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