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