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