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)(26,30)(27,31)(32,35)(33,38)(34,37)(39,40)(1,3)(2,6)(4,7)(5,8)(9,11)(10,14)(12,19)(13,18)(15,23)(16,22)(17,20)(21,24)(25,26,29,30)(27,31,34,37)(28,35,36,32)(33,39,40,38)(1,2,5,4)(3,6,8,7)(9,12,13,20)(10,15,16,24)(11,17,18,19)(14,21,22,23)(25,27)(26,31)(28,33)(29,34)(30,37)(32,38)(35,39)(36,40)(1,4,5,2)(3,6,8,7)(12,20)(15,24)(17,19)(21,23)(25,28,29,36)(26,32,30,35)(27,33,34,40)(31,38,37,39)(10,16)(11,18)(15,24)(17,19)(28,36)(32,35)(33,40)(38,39) 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.