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