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