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