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