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