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