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