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