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