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