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