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