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