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