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