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)(11,17)(12,13)(14,18)(15,27)(16,19)(20,24)(21,25)(22,32)(23,33)(26,28)(29,34)(30,35)(31,36)(37,39)(38,40) involution — undirected(2,5)(3,7)(9,11,16,24)(10,17,19,20)(12,25,27,33)(13,21,15,23)(14,29,31,38)(18,34,36,40)(22,28,39,30)(26,37,35,32)(9,12,13,10,16,27,15,19)(11,20,21,25,24,17,23,33)(14,26,28,18,31,35,30,36)(22,37,29,34,39,32,38,40)(2,5)(6,8)(9,13,16,15)(10,12,19,27)(11,21,24,23)(14,28,31,30)(17,25,20,33)(18,26,36,35)(22,29,39,38)(32,34,37,40)(1,3,4,7)(2,6,5,8)(9,14)(10,18)(11,22)(12,26)(13,28)(15,30)(16,31)(17,32)(19,36)(20,37)(21,29)(23,38)(24,39)(25,34)(27,35)(33,40)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.