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