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