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