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