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