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