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