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