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