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