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