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