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