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