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