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