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