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