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