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