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