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