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