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