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