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