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