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