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