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