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