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