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