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