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