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