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