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