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