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