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