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