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)(11,19,22,34)(12,24,25,39)(14,28,27,18)(16,20,29,23)(17,32,30,26)(21,36,38,31)(33,35,40,37)(2,5)(6,7)(10,15)(11,20)(12,25)(14,27)(16,19)(17,30)(21,37)(22,23)(29,34)(31,33)(35,38)(36,40) involution — undirected(9,11,14,23,13,22,27,20)(10,16,18,19,15,29,28,34)(12,21,26,37,25,38,32,35)(17,31,24,33,30,36,39,40)(9,12,14,26,13,25,27,32)(10,17,18,24,15,30,28,39)(11,21,23,37,22,38,20,35)(16,31,19,33,29,36,34,40)(1,3,4,8)(2,6,5,7)(10,15)(16,29)(17,30)(18,28)(19,34)(24,39)(31,36)(33,40)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.