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