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