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