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