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