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