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