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