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