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