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