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