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