One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,6,4)(3,7,5,8)(9,10,15,13)(11,16,19,21)(12,17,23,22)(14,18,24,20)(26,30)(27,33)(32,35)(34,36)(1,3,6,5)(2,7,4,8)(9,11,15,19)(10,16,13,21)(12,20,23,18)(14,22,24,17)(25,26)(27,31)(28,35)(29,30)(32,37)(33,38)(34,40)(36,39)(1,3,6,5)(2,8,4,7)(11,19)(12,23)(16,21)(17,22)(25,27,29,33)(26,31,30,38)(28,34,37,36)(32,39,35,40)(9,12)(10,17)(11,20)(13,22)(14,16)(15,23)(18,19)(21,24)(25,27)(26,31)(28,36)(29,33)(30,38)(32,40)(34,37)(35,39) involution — undirected(1,4,6,2)(3,7,5,8)(9,13,15,10)(11,21,19,16)(12,17,23,22)(14,18,24,20)(25,28,29,37)(26,32,30,35)(27,34,33,36)(31,39,38,40)(1,5,6,3)(2,7,4,8)(9,14)(10,18)(11,22)(12,16)(13,20)(15,24)(17,19)(21,23)(25,26)(27,31)(28,35)(29,30)(32,37)(33,38)(34,40)(36,39)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.