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