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