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