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