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