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