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)(11,16)(12,25)(13,17)(14,19)(15,20)(18,27)(21,30)(22,36)(23,34)(24,31)(26,33)(28,32)(29,35)(37,40)(38,39)(1,3,4,8)(2,5,6,7)(9,11)(10,16)(12,22)(13,21)(14,23)(15,24)(17,30)(18,29)(19,34)(20,31)(25,36)(26,37)(27,35)(28,38)(32,39)(33,40)(1,2)(3,5)(4,6)(7,8)(10,17)(11,21)(13,14)(18,32)(19,20)(22,35)(23,24)(25,33)(26,27)(30,34)(36,39)(37,38) involution — undirected(2,6)(5,7)(9,12)(10,18)(11,22)(13,27)(14,26)(15,28)(16,29)(17,32)(19,25)(20,33)(21,35)(23,37)(24,38)(30,39)(31,40)(34,36) 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.