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