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