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