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