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