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)(11,20)(12,17)(13,26)(14,30)(15,21)(16,22)(18,29)(19,25)(23,34)(24,32)(27,35)(28,37)(31,38)(33,39)(36,40) involution — undirected(2,5)(6,8)(9,11)(10,15)(12,21)(13,27)(14,23)(16,26)(17,20)(18,37)(19,34)(22,24)(25,31)(28,40)(29,39)(30,38)(32,35)(33,36) involution — undirected(3,7)(6,8)(9,11)(10,16)(12,21)(13,28)(14,31)(15,32)(17,35)(18,38)(19,37)(20,26)(22,29)(23,25)(24,39)(27,40)(30,33)(34,36) involution — undirected(1,3,4,7)(2,6,5,8)(11,21)(15,20)(16,35)(22,27)(23,31)(28,39)(33,37)(34,38)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.