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