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