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