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