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