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