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