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