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