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