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