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