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