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