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