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