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