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)(12,26)(13,20)(14,19)(15,18)(16,25)(17,30)(22,38)(23,33)(24,31)(27,32)(28,36)(29,35)(34,40)(37,39) involution — undirected(1,3)(2,5)(4,8)(6,7)(9,11)(10,16)(12,27)(13,31)(14,25)(15,23)(17,34)(18,24)(19,21)(20,33)(22,30)(26,37)(28,40)(29,39)(32,35)(36,38) involution — undirected(9,12,15,30,14,29,13,28)(10,17,20,26,19,36,18,35)(11,22,23,39,25,40,31,27)(16,32,33,34,21,37,24,38)(2,6)(5,7)(9,13,14,15)(10,18,19,20)(11,23,25,31)(12,28,29,30)(16,33,21,24)(17,35,36,26)(22,39,40,27)(32,34,37,38)(3,8)(5,7)(9,10)(11,24)(12,17)(13,18)(14,19)(15,20)(16,23)(21,31)(22,38)(25,33)(26,30)(27,37)(28,35)(29,36)(32,39)(34,40) involution — undirectedA 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.