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