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