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