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