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