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