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