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