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