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