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