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