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