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