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