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