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