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