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