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