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