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