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