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