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