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