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