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