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