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