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