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