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