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