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