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