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