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