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)(11,16)(12,15)(13,17)(14,18)(19,23)(20,22)(21,24)(26,32)(28,34)(33,35)(36,38)(1,3,5,8)(2,6,4,7)(9,11,14,12)(10,15,18,16)(13,19,21,20)(17,22,24,23)(25,26,31,32)(27,35,29,33)(28,30,34,40)(36,39,38,37)(1,2,5,4)(3,6,8,7)(9,10,14,18)(11,15,12,16)(13,17,21,24)(19,22,20,23)(25,27,31,29)(26,33,32,35)(28,36,34,38)(30,37,40,39)(9,10)(11,15)(12,16)(13,17)(14,18)(19,22)(20,23)(21,24)(25,28,31,34)(26,30,32,40)(27,36,29,38)(33,37,35,39)(9,12,14,11)(10,16,18,15)(13,20,21,19)(17,23,24,22)(25,29,31,27)(26,33,32,35)(28,38,34,36)(30,37,40,39)(1,4,5,2)(3,7,8,6)(9,13,14,21)(10,17,18,24)(11,19,12,20)(15,22,16,23)(25,30)(26,34)(27,37)(28,32)(29,39)(31,40)(33,38)(35,36)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.