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