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