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