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