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