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