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