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