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