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