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