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