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