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