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