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