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