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