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