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