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