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