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