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