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