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