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