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