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