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)(12,26)(13,18,15,20)(16,24)(17,30)(22,36,39,35)(23,33)(25,32)(27,29)(28,34)(31,40,37,38)(2,5)(6,8)(9,11)(10,16,19,33)(12,22)(13,23)(14,25)(15,24)(17,31,26,37)(18,21,20,32)(27,35,34,36)(28,38)(29,40)(30,39)(1,3)(2,6)(4,7)(5,8)(9,10)(11,21)(12,27)(13,20)(14,19)(15,18)(16,23)(17,28)(22,37)(24,33)(25,32)(26,29)(30,34)(31,39)(35,38)(36,40) involution — undirected(3,7)(6,8)(9,12,15,29,14,30,13,28)(10,17,20,34,19,26,18,27)(11,22,24,40,25,39,23,38)(16,31,32,36,33,37,21,35)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.