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