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)(11,14)(12,15)(13,16)(17,19)(18,21)(20,22)(23,24)(25,26,31,29)(27,32,34,28)(30,37,39,33)(35,36,38,40)(2,3)(6,7)(10,11)(13,21)(15,17)(20,24)(25,27)(26,32)(28,29)(30,38)(31,34)(33,36)(35,39)(37,40) involution — undirected(1,3,5,2)(4,7,8,6)(12,19)(15,17)(20,24)(22,23)(26,29)(27,34)(33,37)(35,38)(1,4,5,8)(2,6,3,7)(9,11,14,10)(12,15,19,17)(13,18,21,16)(20,22,24,23)(25,28)(26,27)(29,34)(30,36)(31,32)(33,35)(37,38)(39,40)(9,12)(10,15)(11,17)(13,20)(14,19)(16,22)(18,23)(21,24)(25,29,31,26)(27,28,34,32)(30,37,39,33)(35,36,38,40)(9,13)(10,16)(11,18)(12,20)(14,21)(15,22)(17,23)(19,24)(25,30)(26,33)(27,35)(28,36)(29,37)(31,39)(32,40)(34,38) 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.