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