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