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