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