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