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