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)(28,39,41,50)(29,33,43,49)(32,45,47,36)(37,48,42,44)(40,52,54,55)(46,53,56,51)(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)(28,36,41,45)(29,42,43,37)(32,39,47,50)(33,48,49,44)(40,53,54,51)(46,55,56,52)(3,7)(5,8)(9,12,14,13)(10,16,17,22)(11,19,21,20)(15,23,18,24)(25,28,27,36,30,41,38,45)(26,32,31,39,34,47,35,50)(29,40,37,51,43,54,42,53)(33,46,44,52,49,56,48,55)(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)(30,43)(31,44)(32,46)(34,49)(35,48)(36,51)(38,42)(39,52)(41,54)(45,53)(47,56)(50,55)(3,7)(5,8)(9,13,14,12)(10,16,17,22)(11,20,21,19)(15,23,18,24)(26,34)(29,43)(31,35)(32,47)(37,42)(39,50)(40,54)(51,53)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.