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