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