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