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