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