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