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)(27,33)(28,34)(30,36)(32,37)(35,39)(38,40)(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)(27,30)(28,32)(29,31)(33,36)(34,37)(35,38)(39,40) 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)(25,27,34,39,29,35,28,33)(26,30,37,40,31,38,32,36)(3,8)(6,7)(12,20)(15,24)(17,19)(21,23)(25,26)(27,30)(28,32)(29,31)(33,36)(34,37)(35,38)(39,40) involution — undirected(10,16)(11,18)(15,24)(17,19)(26,31)(27,35)(32,37)(33,39) 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.