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