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