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