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