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