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