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