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