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