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