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