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