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