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