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