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