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