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