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