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