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