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