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