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