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