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