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