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