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