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