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