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