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