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